Abstract: The pass band filter has planar ring resonators arranged in pairs partly side-by-side and partly one above the other and a housing cover for each resonator. Each resonator includes a respective substrate provided with upper and lower conductive layers of high temperature superconductor material on respective opposite sides of the corresponding substrate, so that each planar ring resonator is operable in an edge-current-free TM010-oscillator mode. A respective coupling hole of radius r.sub.i is provided in the lower conductive layer (3) of each resonator and the lower conductive layers of both resonators in each pair face each other so that both resonators are coupled. Each housing cover has a respective truncated cone-shaped step ring (20) having a corresponding inner housing cover radius (r.sub.G). The radius ratio r.sub.i /r.sub.a (r.sub.